The present invention relates to a power tool with an overload protection device.
Power tools according to the related art are usually equipped with a protection mechanism that is integrated in the electronics. As soon as a certain power stage is exceeded when working with the power tool, the machine is automatically shut off via its overload protection function (“torque function”). A desired torque is set as the default by electronic elements. Mechanically-acting release couplings are used, e.g., to limit torque. Electronic torque limitation enables the device to be shut off immediately and with virtually no backlash. This function is active, in principle, in many power tools. This has the disadvantage, however, that maximum power is not available with power tools of this type, because the device is shut off automatically before maximum power is reached. With other power tools, the overload protection function may be switched on and off manually, e.g., using a switch or an actuator wheel, with this function being active in all gears. This has the disadvantage, however, that the operator may overheat the motor when the device is operated in second gear (with the overload protection function activated), without his having first switched to first gear (in which overheating possibly may not occur). The speed is reduced via the electronics, which automatically reduce the speed when torque is high in maximum-load operation. Since the device is not shut off automatically, the operator is not forced to switch to first gear.